Bowling pin with hollow metal core comprising a plurality of sections



. F. BAUER Jan. 11, 1966 LLOW METAL CORE COMPRISING LITY OF SECTIONSBOWLING PIN WITH A PLURA Filed Feb. 26, 1963 2 Sheets-Sheet 1 2.. NEW

INVENTOR ALFRED F. BAUER ATTORNEYS A. F. BAUER HHO Jan. 11, 1966 BOWLINGPIN LLOW METAL GORE COMPRISING A URALITY OF SECTIONS 2 Sheets-Sheet 2Filed Feb. 26, 1965 INVENTOR ALFRED F. BAUER BY 2 22 ATToRNEYs UnitedStates Patent 3,228,687 BOWLING PIN WITH HOLLOW METAL CORE COM- PRISINGA PLURALITY 0F SECTIONS Alfred F. Bauer, Toledo, Ohio, assignor toNational Lead Iompany, New York, N .Y., a corporation of New ersey FiledFeb. 26, 1963, Ser. No. 261,055 4 Claims. (Cl. 273-'82) This inventionrelates to a metal bowling pin and is particularly directed to a plasticcovered, die cast pin having greatly improved balance, durability andease of manufacture.

Bowling pins in the past have generally been made of wood and moreparticularly of hard maple. In recent years, the supply of the type ofmaple used for wooden bowling pins has diminished in this country, whilethe increase in popularity of the sport of bowling has produced a demandfor greater and greater numbers of bowling pins. The typical woodbowling pins has several inherent disadvantages. One disadvantage isthat the wooden bowling pin becomes marred and chipped after arelatively short time thus making it necessary that the pins be removedfrom service, turned down a lathe, and then refurbished by applicationof a new plastic outer layer. Another disadvantage is that the reducedneck section of a wooden bowling pin is very susceptible to failure byway of breakage.

Also, during the summer months, when the relative humidity is high themoisture in the air affects the bond between the wooden core and theplastic outer layer whereby they tend to become separated. During thesubsequent winter months, or in periods of low relative humidity, thewood in the bowling pin shrinks up to five percent and the plastic outerlayer has a tendency to become separated from the wooden core to such adegree that the pin must be taken out of service. When this happens thepins must be placed in a controlled humidity room for approximately 48hours where swelling of the wood takes place and again provides propercontact between the plastic outer layer and the wooden core.

Since the rate of recovery is greater for plastic than it is for wood,upon impact between the wooden bowling pin and the bowling ball, theplastic recovers its original shape at a faster rate than the woodencore whereby there is an additional tendency of the plastic outer layerto separate from the wooden core.

One of the objections to prior art metal bowling pins was that some ofthem were constructed in two parts or [halves and joined together with alongitudinal connection or seam. When impact occurred between thebowling ball and the pin, the bowling pin had a tendence to split alongthe longitudinal seam.

The metal portion of the pin has been formed by a sand casting process.When a sand cast-ing process is used in producing a metal bowling pincore, the resultant metal core does not have desirable physicalcharacteristics. Because of the inherent characteristic of the sandcasting process, the wall thicknesses of the core cannot becontrol-ledto close tolerances. The nonuniform wall thickness of themetal core produced by. the sand casting process results in a bowlingpin which is unbalanced and thereby unacceptable.

It is the primary object of the present invention to produce a metal diecast bowling pin, which is constructed to close tolerances therebyresulting in a balanced bowling pin.

Another object of the present invention is to provide a metal bowlingpin of the same size, shape and weight distribution of a standard woodenbowling pin.

Still another object of the invention is to provide a "ice metal bowlingpin which gives the same sound and action as does a standard woodbowling pin when struck by the bowling ball, or when the bowling pinsfall upon the lanes or alleys.

A further object is to provide a bowling pin which can be kept incontinual use throughout an entire bowling seas-on.

Still another object of this invention is to provide a metal bowling pinwhich does not have a tendency to split or separate under the impact ofa bowling ball.

Another object of this invention is to provide a metal bowling pin whichhas a neck section of greater strength and durability than a typicalwood bowling pin.

Further objects of this invention will become apparent from thefollowing specification and drawings, in which:

FIG. 1 is a front elevation view showing a bowling pin embodying theinvention;

FIG. 2 is a vertical cross-sectional view, taken along the line 22 ofFIG. 1 and drawn on an enlarged scale, wherein a portion of the sounddeadening layer has been removed to show the use of reinforcing ribs.Several of the reinforcing ribs have been omitted in this figure forpurposes of clarity;

FIG. 3 is a vertical cross-sectional assembly view of another embodimentof the invention, in which only the three cast sections are shown;

FIG. 4 is a horizontal cross-sectional view, taken along the line 44 ofFIG. 3 and drawn on an enlarge scale, wherein an outer layer of plasticmaterial and an inner layer of sound deadening material are shown; and

FIG. 5 is a horizontal cross-sectional view taken along the line 55 ofFIG. 2, in which a portion of the inner sound deadening layer is shown.

Briefly, the present invention com-prises a die cast metal bowling pinwhich is to be used as a substitute for the presently used hard maplebowling pin. The metal bowling pin comprises a sectional hollow, diecast light metal (aluminum or magnesium alloy) core, said sections beingjoined together by a welding process, an adhesive bonding process, apressure fit process, or by a combination of the preceding methods. Alayer of sound deadening material is placed on the interior surface ofthe hollow metal core and a layer of a semi-flexible plastic material isformed over the outer surface of the metal core.

An embodiment of a metal bowling pin, according to the invention isgenerally indicated at 10. The metal bowling pin 10 comprises a hollowmetal core 11 constructed of three hollow metal die cast sectionsnamely: a lower cup-like section 12, an intermediate neck section 13,and cap section 14. The three sections of the bowling pin, namelysections 12, 13 and 14, are joined together at joints 15 and 16 whichare transverse to the longitudinal axis of the bowling pin. It should benoted that the lower transverse joint 16 is located at a point above thepoint of impact P between a standard 16 pound bowling ball and thebowling pin 10 and the upper transverse joint 15 is located well abovethe point of impact. Because of the lack of a longitudinal joint and thepositions of the transverse joints, at no time will a bowling balldirectly strike the bowling pin at a joint, therefore the tendency ofthe bowling pin to split apart at the joints is greatly reduced.

A plurality of integrally die cast and circumferentially spacedreinforcing ribs 17 are provided in one embodiment of the invention, onthe interior surface of die cast sections 12 and 13. The reinforcingribs 17 extend longitudinally on the interior surfaces of the bowlingpin 10 and are formed so they extend beyond their respective castings 12and 13 and engage frictionally with the body of the adjacent casting.For example, a reinforcing rib 17a which is. die cast integrally withlower cup-like section 12, extends past the lower transverse joint 16.The

exteriorsurface .18 of the reinforcing rib 17a has ap' proximately thesame shape as the surface 19 of the inter mediate neck section 13 at thesame horizontal plane. The reinforcing rib 17a is cast so that the upperportion which engages with intermediate neck section 13 has an exteriorradius slightly greater than the interior radius of the intermediateneck section 13. Therefore when the castings 12 and 13 are joinedtogether the upper portion of reinforcing rib 17a serves as acantilever. The compression fit resulting from the difierence in radiiapplies force along the surface of the cantilever whichresults in acounteracting moment which in turn applies force to the interior surface19 of the die cast section 13.

These plurality of engaging ribs 17 reinforce the bowling pin when it isstruck by a bowling ball and also during the application of an outerlayer of plastic material 25 as will become apparent hereinafter,

The three die cast metal sections 12, 13 and 14 are joined togetherpreferably by the Sciaky Welding method, which is a flash weldingprocess in which the two sections to be joined are made electrodes. TheSciaky method is used because of its characteristic fast cycle ofwelding which confines the welding heat almost completely to the ends ofthe surfaces to be welded and thus prevents the body of the sections ofthe metal core 11 from overheating.

The intermediate neck section 13 and the cap section 14 can be joinedtogether by other methods, for example, by the use of a resin-bindingmaterial such as an epoxy resin. Shoulders 20 are provided on thesections 12 and 13, and sections 13 and 14 respectively, to serve asguides to position the sections in a uniform manner, during the weldingor bonding processes.

The production of the hollow metal core 11 by a die casting processresults in a core which has extremely uniform Wall thickness. Forexample, the wall thickness of the hollow metal core, in the instantinvention, it meas wed in a plane perpendicular to the longitudinal axisof the bowling pin does not vary more than 0.0015 inch. It is veryimportant in the metal bowling pin art that the wall thicknesses of thehollow metal cores be kept to extremely close tolerances so that thecompleted bowling pin is symmetrical and therefore balanced. Such abalanced bowling pin cannot be produced, with any degree of consistency,by a sand casting process in which sand cores must be used,

FIG. 3 shows another embodiment of the invention which depicts anothermethod of joining the individual sections 12, 13 and 14 together. Inthis method the die cast sections 12, 13 and 14 are cast with fingers 21on the lower section 12 and fingers 22 on the intermediate section 13.The fingers 21 and 22 extend beyond their respective castings 12 and 13and interengage with the body of the adjacent casting. 'This forms avery firm joint and when the two sections 12 and 13 are pressedtogether, the resiliency of the metal makes it virtually impossible topull them apart. Intermediate neck section 13 and'cap section 14 arejoined'in a similar manner.

After the assembly of die cast sections 12, 13 and 14, a rubber-likesound deadening material 23, such as a foaming polyurethane spray, isapplied to'the inner wall of each of the three sections 12, 13 and 14.The sound deadening material 23 is, for example, sprayed into theassembled die cast sections 12, 13 and 14, through an axial opening 24which is formed in the bottom of lower cup-like section 12. Thisrubber-like sound deadening material 23 is provided on the interiorsurface of the process,-and after the sound deadening material 17 hasbeen applied, an outer layer of plastic material 25 is applied to theassembled castings. Cap section 14 is provided with an axial opening 26which engages with a centering pin located in the plastic coating mold(not shown). The outer layer of plastic material 25 is applied in themold under pressure and the plurality of reinforcing ribs 17 prevent thehollow metal core 11 from deforming during this process. If reinforcingribs are not used, the outer layer of plastic material 25 maybe appliedby low pressure molding process. After the outer plastic layer 25 isapplied, a nylon insert 27 is adhesively or otherwise secured to thelower cup-like section 12. Insert 27 defines a shoulder 28 which guardsthe lower end 29 of the outer plastic layer 25 and serves to protect thelanes or alleys from excessive marin'g and is constructed in accordancewith American Bowling Congress regulations.

The bowling pin 10 is constructed so that the weight of any segment ofthe bowling pin defined by two parallel planes which are perpendicularto the longitudinal axis of the bowling pin is the same as the weight ofa similar segment of a hard maple bowling pin defined by the sameplanes.

The thickness of the outer plastic and the hollow metal core isdetermined by the relative density or specific gravity of the plasticused in the outer layer and the relative density or specific gravity ofthe metal used in the core with relation to the specific gravity of hardmaple. Therefore, as previously discussed, a unit cross section of theembodiment of the present invention will weigh approximately the same asa unit cnoss section, taken at the same vertical position, of a hardmaple bowling pin.

While the invention has been disclosed in conjunction v with a specificform and disposition of the parts, it should hollow metal core 11 toreduce the resonance of the hollow metal core 11. After the sounddeadeninglay'er 23 is applied, the natural frequency of vibration of thepin is such that the sound of a standard hard maple bow1- ing pin whenit falls or is struck by a bowling ball is very closely reproduced. 1

After the three sections 12, 13 and 14 have been joined together byeither the welding process, or the press fit be expressly understoodthat numerous modifications and changes may be made without departingfrom the spirit and scope of the appended claims.

What I claim is: v

1. A bowling pin comprising a die cast hollow light metal core, saidcore comprising a plurality of die cast sections joined together inend-to-end relation, whereby the joints formed are transverse to thelongitudinal axis of said bowling pin, at least one of said die castsections having a plurality of integrally cast and circumferentiallyspaced reinforcing ribs extending longitudinally along its interiorsurface, said reinforcing ribs extending beyond one end of said die castsection and interengaging with the interior surface of the adjacent diecast section, a coating of sound deadening material on the inner surfaceof said metal core, a layer of a plastic material on the outer surfaceof said metal core, and a protective insert secured to the bottom ofsaid bowling pin.

2. A bowling pinaccording to claim 1, wherein the wall thickness of saidhollow metal core, if measured in a plane perpendicular to thelongitudinal axis of said bowling pin, does not vary more than 0.0015inch.

3. A bowling pin according to claim 1, in which said hollow metal corecomprises three die cast sections joined together in end-to-endrelation, whereby the upper and intermediate sections and the lower andintermediate sections are joined together at a point above the point ofimpact between'a standard bowling ball and said bowling pin.

4. A bowling pin comprising a die cast hollow metal core, said hollowmetal core comprising three die cast sections welded together inend-to-end relationship, where by the joints formed are transverse tothe longitudinal axis of said bowling pin and wherein the wall thicknessof said hollow metal core, if measured in a plane perpenduclar to thelongitudinal axis of said bowling pin does not vary more than 0.0015inch, at least one of said die cast sections having a plurality ofintegrally cast and circumferentially spaced reinforcing ribs extendinglongitudinally along its interior surface, said reinforcing ribsextending beyond one end of said die cast section and 5, inter-engagingwith the interior surface of the adjacent die cast section, a coating ofsound deadening material on the inner surface of said metal core, alayer of a plastic material on the outer surface of said metal core, anda protective insert secured to the bottom of said bowling pin.

References Cited by the Examiner UNITED STATES PATENTS 1,060,932 5/1913Mussey 273-82 1,491,279 4/1924 Stewart 273 s2 10 2,166,950 7/1939 Germanet a1 273-82 6 2,340,156 1/ 1944 Taylor et a1. 273-72 3,025,060 3/1962Hollingsworth 27382 3,044,777 7/ 1962 Friedman 273-82 FOREIGN PATENTS884,983 12/1961 Great Britain.

DELBERT B. LOWE, Primary Examiner.

RICHARD C. PINKI-LAM, Examiner.

GERALD L. PRICE, Assistant Examiner.

1. BOWLING PIN COMPRISING A DIE CAST HOLLOW LIGHT METAL CORE, SAID CORECOMPRISING A PLURALITY OF DIE CAST SECTIONS JOINED TOGETHER INEND-TO-END RELATION, WHEREBY THE JOINTS FORMED ARE TRANSVERSE TO THELONGITUDINAL AXIS OF SAID BOWLING PIN, AT LEAST ONE OF SAID DIE CASTSECTIONS HAVING A PLURALITY OF INTEGRALLY CAST AND CIRCUMFERENTIALLYSPACED REINFORCING RIBS EXTENDING LONGITUDINALLY ALONG ITS INTERIORSURFACE, SAID REINFORCING RIBS EXTENDING BEYOND ONE END OF SAID DIE CASTSECTION AND INTERENGAGING WITH THE INTERIOR SURFACE OF THE ADJACENT DIECAST SECTION, A COATING OF SOUND DEADENING MATERIAL ON THE INNER SURFACEOF SAID METAL BORE, A LAYER OF A PLASTIC MATERIAL ON THE OUTER SURFACEOF SAID METAL CORE, AND A PROTECTIVE INSERT SECURED TO THE BOTTOM OFSAID BOWLING PIN.